The subject matter of the present disclosure broadly relates to the art of vehicle powertrains and, more particularly, to an electrically-variable powertrain for an all-wheel drive vehicle. The subject matter finds particular application and use in conjunction with high-performance, all-terrain personnel transport vehicles, and will be described herein with particular reference thereto. However, it is to be appreciated that the subject matter of the present disclosure is also amenable to use in other applications and environments, such as in passenger vehicles, light-duty trucks, sport-utility vehicles and other transport vehicles, for example. Thus, it will be appreciated that any specific reference herein to use in association with high-performance, all-terrain personnel transport vehicles is merely exemplary.
It will be appreciated that the present disclosure includes numerous rotating components (e.g., rotors, crankshafts, axles, gears) that can rotate at different speeds, rotate in different directions, transmit or carry different torsional loads, and/or transmit or carry different horsepower loads, as either inputs or outputs. For ease of reading and understanding, terms such as rotational connection, rotational output, rotational power source, and the like, have been used to broadly refer to any such rotational, torsional or power condition. Additionally, as used herein with reference to certain elements, features, components, structures and/or actions (e.g., “first electric machine,” “second electric machine,” “first rotational connection” and “second rotational connection”), numerical ordinals merely denote different singles of a plurality and do not imply any order or sequence unless specifically defined by the claim language.
Personnel transport vehicles of a variety of types and kinds are known and commonly used. In many of such known vehicles, the powertrain and other mechanical components are centrally located on the vehicle typically toward the bottom side thereof. It is well recognized that components of greater size and/or mass are often less significantly damaged by projectiles and the discharge from explosive ordinance than are components of lesser size and/or mass. Though known arrangements provide some additional shielding against discharges from ordinance positioned underneath the vehicle, known arrangements do not utilize the mass of the powertrain components as supplemental shielding of the personnel compartment of the vehicle.
Additionally, known hybrid powertrains typically control the supply of motive power to the vehicle under an axle-by-axle type of operation. This is believed to be the case even when such a hybrid powertrain is used on an all-wheel drive vehicle. As such, as a vehicle is traveling on a succession of dry and icy surfaces, there is often only a small interval during which the axles are operating under different conditions from one another. As a vehicle is traveling along a partially snow-covered road, one side of the vehicle may be operating on dry pavement while the other side of the vehicle may be operating on snow and ice. Under such conditions, known hybrid powertrains are believed to provide less than optimal control of the vehicle.
Furthermore, known hybrid vehicles commonly operate in a manner that results in asymmetrical cornering of the vehicle. That is, these vehicles are believed to operate such that the front and rear wheels of the vehicle track along slightly different paths as the vehicle negotiates a turn or corner. In some circumstances, such operation may be undesirable because it could be possible for one wheel on one side of the vehicle to avoid hitting an object laying on the ground while the second wheel on that side of the vehicle might contact the object, such as during a cornering maneuver, for example.
Accordingly, it is believed desirable to develop an electrically-variable powertrain for an all-wheel drive vehicle as well as methods of operation that may overcome one or more of the foregoing and other disadvantages.